Disclaimer: settings and characters as depicted in BBC series not mine. No money being made. Plot is mine.
Increasing the Level of Difficulty
Moriarty did not wait for the fallout to settle from Dimmock's frame-up. The next task was ready and waiting as Sherlock returned to Baker Street after watching Lestrade haul Dimmock over the coals for his 'blunders'. John had insisted on carefully documenting every step of their plan, in order to be able to undo the damage once this was all over. They now had an electronic and paper record of Dimmock's carefully planned downfall to present to the Yard – Sherlock hoped that the young man was nowhere near himself or John when the news broke.
"Theft?" John frowned as Sherlock laid the details of the next task out, "That's a bit… pedestrian, isn't it? We've gone from interfering with the police and relocating criminals across international lines to plain old theft?"
"This is a little more than theft, John," Sherlock sighed, "We're talking about stealing information, not objects."
"Espionage," John grinned, "Very James Bond."
"Please, not another movie marathon," Sherlock groaned, giving his flatmate a distinctly pleading look. Those films had been a waste of time, though he had been in John's good books for a few days afterwards, "That was a day of my life I'll never get back."
"Ah, but this time you'll get the snuggling that traditionally goes with staying it to watch a movie," John laughed and Sherlock pulled a face before returning his attention to the matter at hand.
"So what is it that Moriarty wants, and how safe is it to give to him?" John abandoned the teasing, proving once more that he had the right priorities when it came to their lives together. Sherlock offered him a twitch of the lips to convey his approval and turned back to their instructions.
"He wants a passkey – a computer code that will allow him to access governmental databases and archives," Sherlock frowned, "It would allow him to by-pass certain security features in the governmental network. He doubtless has a hacker that could take the passkey and leverage access into every level of the network."
"He could topple national security, set the interest rates or just rob the government blind," John frowned, "That's… enormous. Can we risk failing this one?"
"John, if we were to so much as hint to Mycroft that we wanted the passkey my own brother would lock us up for the rest of our lives," Sherlock said crossly, "We're supposed to fail."
John thought for a moment. It was fascinating to watch the process and Sherlock was quite proud that it only took his flatmate forty two seconds to realise what the real purpose of the task was.
"It's a distraction. While the government is running around looking for the thieves, Moriarty has another operative go after the real target… and that will get blamed on the first set of thieves," John said flatly. Sherlock patted his knee with his palm and John sighed.
"I'll need to set something up that will appear plausible to both Moriarty and the various intelligence officers that monitor this sort of thing," Sherlock mused aloud, now rubbing his palm in absent minded circles over John's kneecap, "And I'll need to ensure that I am called into the investigation so that I can sabotage it as needed."
"Is there any indication as to what Moriarty is really looking for? Obviously he'll suspect that you know you're being set up to fail, so will he also expect you to deduce his real target?" John asked. Sherlock froze for a long moment, staring into space as his mind worked furiously.
"I'm not sure," he murmured in reply, "John, I need you to go up to your room for a while and be absolutely still. Take some books to read. I need to think."
Before the Pool, Sherlock would have thrown his Heart out of the flat with instructions not to come back for a few hours – with Moriarty around that was simply no longer an option. John was to be kept safe at all costs, but Sherlock wasn't sure that he'd be able to concentrate like he needed to with John in the same room, even if he was silent and mostly still.
"Sherlock! Where are your manners?" Martha scolded from the door, "You come down with me, John dear. Sending you to your room as if you were a child, the very idea!"
"I don't mind, Mrs Hudson. You know what he's like when he needs to think," John grinned and slipped out from under Sherlock's hand and going to the shelves. He grabbed a couple of books and followed their landlady down the stairs without a backwards look or a hint of complaint. Sherlock spent a moment reflecting on his gratitude for John's steady nature and then put it aside, locating his nicotine patches and settling onto the couch for a good hard think.
The problem as he saw it was that they needed to fail in such a way as to prove their mettle, while at the same time assessing the real target. Moriarty was after something particular that would allow him to increase his resources or network. The question was: how much of an advantage was safe to give the other man – how safe was it to let him have what he wanted? Sherlock was supposed to be taking Moriarty down, not helping to build his empire. Although he and his Heart both knew that their goal would not be achieved overnight, Sherlock didn't want to be still at it a year from now.
Above all else, Mycroft was not to be involved in this – if something went wrong they would need him to be above reproach in order to intervene for them. That they were keeping the man in the dark was just what John would have called 'icing on the cake'. With all that in mind, Sherlock began planning the contacts and resources he would need to tap to get the task begun. John would need to be involved as more than a peripheral in this – there was no one else that Sherlock trusted and it would allow him to genuinely establish his partner's importance in completing the tasks.
When Sherlock was satisfied with his plans he popped up off the couch and clattered down the stairs, dimly recognising that it was quite dark now as he went in search of Mrs Hudson and John. They were in her front room, assembling bookcases from Argos. Sherlock hadn't heard the cases being delivered, which meant…
"You went out!" he scowled, "John, it's not safe!"
"I will not cower in Baker Street," John replied in a calm voice. That voice always meant trouble, so Sherlock folded his arms and pressed his lips into a cross line, knowing full well that a silent expression of his disapproval would be more effective than a verbal one at this point.
"I took my gun with me," John sighed, "We were quite safe."
"You did?" Martha exclaimed, looking quite startled and John shot her an amused look, nodding to his jacket which was draped in an armchair.
"I wouldn't take risks with your security, nor mine," he said firmly, "So stop pouting Sherlock and come hold the other side of this for me."
"Tea please," Sherlock told Martha, who rolled her eyes and headed off to her kitchen, muttering under her breath the familiar refrain. John grinned at him over the pieces of furniture and started wielding an allen key energetically.
"I'll need you to work with me on this one," Sherlock informed John, "We'll start tonight, and you'll have to come out with me when I meet some of my contacts. You'll need to coordinate the information flow and be my rep."
"Can do," John nodded, coming around to Sherlock's side, "Move your hand down."
Sherlock moved his hand as directed and watched as John finished his assembly task, helping to lift the bookcase upright and place it against the wall. Martha came in with the tea while John shoved the packing materials outside, to later be dragged around the corner to a skip. Sherlock sat and drank his tea while John and Martha loaded books onto the case, along with a few knickknacks. Once done he tossed John's coat to him and led him out, deigning to carry a piece of the packing box on the understanding that John would move faster.
"We've got to find Ferret and Badger tonight," Sherlock informed his Heart as they ducked down a back alley in a familiar shortcut, "They're usually hanging around Charing Cross Station at this time of night. They'll be able to get hold of three others that I need, and from there we'll begin testing security. Ferret is trustworthy up to a point, but Badger is a double agent for Moriarty, so watch what you say around him."
"Got it," John nodded, "By testing security I take it you mean picking pockets and stealing bags?"
"Very good John, you're starting to get the idea," Sherlock said in admiration, to which his flatmate snorted in reply. Sherlock smirked at him and headed to the left, aiming for a shortcut that would take them across the roofs.
He was very pleased to see that John was keeping up with him easily, though there was a slight hitch in his breath when he stretched on the left side. Making a mental note to keep an eye on his partner, Sherlock led them into the night.